javascript 使用 Underscore JS 对 JSON 数组进行分组和聚合
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Group by and aggregation on JSON array using Underscore JS
提问by Shailesh
I have a json array object . I want to group by data based on column "FlexCategoryName" and perform aggregation on matrix columns such as avg of "cost" ,sum of "clicks" etc . Below are JSON array Object
我有一个 json 数组对象。我想根据基于列“FlexCategoryName”的数据进行分组，并对矩阵列执行聚合，例如“成本”的平均值、“点击次数”的总和等。下面是 JSON 数组对象
Array[100]
0: Object
1: Object
2: Object
3: Object
0: Object
0：对象
Clicks: 1067
Cost: 4094.2
Date: "2/8/2014"
FlexCategoryName: "Cat1"
Impressions: 65943
Leads: 20
VENUE_ID:1
VENUE_ID:1
1: Object
1：对象
Clicks: 106
Cost: 409
Date: "2/8/2014"
FlexCategoryName: "Cat2"
Impressions: 65941
Leads: 21
VENUE_ID:1
2: Object
2：对象
Clicks: 106
Cost: 409
Date: "2/8/2014"
FlexCategoryName: "Cat2"
Impressions: 10
Leads: 21
VENUE_ID:2
3: Object
3：对象
Clicks: 106
Cost: 409
Date: "2/8/2014"
FlexCategoryName: "Cat3"
Impressions: 10
Leads: 21
VENUE_ID:2
4: Object
4：对象
Clicks: 20
Cost: 10
Date: "2/8/2014"
FlexCategoryName: "Cat5"
Impressions: 10
Leads: 21
VENUE_ID:3
How to use Underscore JS to perform group by and aggregation on matrix columns .
如何使用 Underscore JS 对矩阵列进行分组和聚合。
Expected Output
预期产出
0: Object
Cost: sum of all cost based on FlexCategoryName Cat1
FlexCategoryName: "Cat1"
Impressions: sum of all Impressions based on FlexCategoryName Cat1
1: Object
Cost: sum of all cost based on FlexCategoryName Cat2
FlexCategoryName: "Cat2"
Impressions: sum of all Impressions based on FlexCategoryName Cat2
回答by thefourtheye
var _ = require("underscore");
function sum(numbers) {
return _.reduce(numbers, function(result, current) {
return result + parseFloat(current);
}, 0);
}
var result = _.chain(data)
.groupBy("FlexCategoryName")
.map(function(value, key) {
return {
FlexCategoryName: key,
Cost: sum(_.pluck(value, "Cost")),
Impressions: sum(_.pluck(value, "Impressions"))
}
})
.value();
console.log(result);
Output
输出
[ { FlexCategoryName: 'Cat1', Cost: 4094.2, Impressions: 65943 },
{ FlexCategoryName: 'Cat2', Cost: 818, Impressions: 65951 },
{ FlexCategoryName: 'Cat3', Cost: 409, Impressions: 10 },
{ FlexCategoryName: 'Cat5', Cost: 10, Impressions: 10 } ]
If you want to find average values instead of sum, then just change the function.
如果你想找到平均值而不是总和，那么只需更改函数即可。
Edit:If you want to group based on more than one fields, you can nest the grouping like this
编辑：如果要基于多个字段进行分组，可以像这样嵌套分组
var result = _.chain(data)
.groupBy("FlexCategoryName")
.map(function(value, key) {
return _.chain(value)
.groupBy("VENUE_ID")
.map(function(value1, venue_id) {
return {
FlexCategoryName: key,
Cost: sum(_.pluck(value1, "Cost")),
Impressions: sum(_.pluck(value1, "Impressions")),
VENUE_ID: venue_id
}
})
.value();
})
.value();
